From modeling to remodeling of upper airways: Centrality of hyaluronan (hyaluronic acid).

After traumatic events (accidental or surgical), the respiratory tract activates specific and prolix repairing mechanisms which tend to claw back the primitive differentiated state. The attempt of reactivation of the normal tissue functions is called 'remodeling' and its aim is to reinstate the modeling mechanisms that existed before the damaging event or the pathology's establishment. Endoscopic sinus surgery represents the gold standard treatment for inflammatory, malformative, benign, and, in selected cases, malignant diseases. The surgical technique is commonly described as minimally invasive as the nostrils are used as an access route and therefore does not leave any external scars. Currently, the surgical procedures, even though minimally invasive regarding the way in, are in fact widely destructive towards the surgical target. The healing process and re-epithelialization will depend on the amount of bony tissue that has been exposed and it will be important to stratify the different surgical typologies in order to foresee the increasing difficulty of mucosal healing process. As far as upper inflammatory diseases are concerned, recent studies demonstrated how intranasal hyaluronic acid can positively regulate mucosal glands secretion and modulate inflammatory response, being a useful tool for the improvement of remodeling after endoscopic sinus surgery. Acid has shown to be able to regulate mucosal glands secretion and modulate the inflammatory response.